1. Field of the Invention
The present invention relates to a single thin plate storage container that stores a thin plate such as a semiconductor wafer, a memory disc, and a liquid crystal glass substrate and is used for storage, transport and manufacturing process, etc., and shock-absorbing support members used therein.
2. Description of the Background Art
Single thin plate storage containers for storing a single thin plate such as a semiconductor wafer, for purpose of storage or transport, are generally known. One example of a single thin plate storage container is a robot package described in International Application Publication No. WO 92/21145. This robot package has a compartment for wafer storage. A wafer is inserted into the compartment for storage and transport.
There is also a single thin plate storage container composed of a shallow dish-shaped body and a lid.
However, with such a robot package as mentioned above, it is not easy to put a wafer in or take it out from the compartment, resulting in a limitation in workability.
Meanwhile, the single thin plate storage container composed of a shallow dish-shaped body and a lid makes it easier to put in and take out a wafer than the above mentioned robot package, but this container also requires the wafers to be taken out from above. In the case with a dish-shaped container, since the stored wafer is surrounded by the wall of the container, it is impossible to insert vacuum tweezers of a transfer apparatus in a lateral direction. This requires the wafer to be taken out from above, causing insufficient workability.
In addition, with a thinner and larger wafer, it is difficult to lift the wafer held only at its edge from the viewpoint of strength, which would also pose a problem of unsatisfactory workability.
Especially, for a single thin plate storage container handling an extremely thin silicon wafer, it is important to consider not only the manner of putting in and taking out a wafer but also the manner of holding the wafer in the single thin plate storage container. That is, the silicon wafer is extremely thin as 25 to 400 μm as and thus can be easily bent like paper due to its lack of strength. Thus, the silicon wafer would be largely bent when being simply held at its edge, which leads to such troubles as breakage of the silicon wafer and damage to a microcircuit formed on the silicon wafer, etc.
In general, such an extremely thin silicon wafer is handled with its both sides covered with a protective film. The protective film reinforces the wafer and also makes it easy to handle. In this case as well, however, the silicon wafer will be bent heavily when being held at its edge, which may cause damage to a circuit formed on the silicon wafer surface, etc.